I'm upgrading my GPU from a 9800GT to a GTS450 (GDDR5 ver) which I managed to get off a friend cheaply but the problem is now I believe my current PSU is incompatible due to the Amps on the 12v are just too low (requirements is 22Amps).
The problem with that PSU is that it's not really a 450W PSU. It's MAX power output is 450W but i would be surprised if it's continuous output was even 350W if that. For that card (or any card that requires external power) I would suggest a power supply with AT LEAST 500 Watts of continuous power and preferably a single rail design with at least 38 amps on the rail. Afew suggestions would be